New ink

Abstract

The present invention relates to a suspension comprising at least one pigment, a dispersing agent and a solvent. Preferably, the suspension has a volatile organic compound (VOC) content less than 3% w/w. Furthermore, the invention relates to an ink comprising the suspension and a printing process comprising at least one step of using the ink.

1 . A suspension comprising at least one pigment, a dispersing agent and a solvent,
 wherein said at least one pigment is present in a concentration comprised between 18 and 65% weight/weight (w/w) with respect to the weight of the suspension,   wherein the dispersing agent is present in the suspension in a concentration comprised between 5 and 55% w/w,   wherein the solvent is an aqueous solvent and is present in a concentration comprised between 25 and 80% w/w and   wherein the suspension has a volatile organic compound (VOC) content of less than 3% w/w.   
     
     
         2 . The suspension according to  claim 1 , wherein the VOC content is less than 1% w/w with respect to the weight of the suspension. 
     
     
         3 . The suspension according to  claim 1 , wherein the aqueous solvent is water, preferably distilled water. 
     
     
         4 . The suspension according to  claim 1 , wherein said at least one pigment is present in a concentration comprised between 20 and 60% w/w with respect to the weight of the suspension. 
     
     
         5 . The suspension according to  claim 1 , wherein said at least one pigment is present in a concentration comprised between 20 and 35% w/w. 
     
     
         6 . The suspension according to  claim 1 , wherein the dispersing agent is present in a concentration comprised between 10 and 35% w/w with respect to the weight of the suspension, preferably comprised between 15 and 25% w/w. 
     
     
         7 . The suspension according to  claim 1 , wherein the solvent is present in a concentration comprised between 20 and 40% w/w with respect to the weight of the suspension. 
     
     
         8 . The suspension according to  claim 1 , wherein the solvent is present in a concentration comprised between 50 and 65% w/w with respect to the weight of the suspension. 
     
     
         9 . An ink comprising the suspension according to  claim 1 , wherein the ink has a VOC content less than 1% w/w. 
     
     
         10 . The ink according to  claim 9 , wherein the suspension is present in a concentration comprised between 5 and 35% w/w with respect to the weight of the ink, preferably comprised between 8 and 30% w/w, more preferably comprised between 10 and 20% w/w. 
     
     
         11 . The ink according to  claim 9 , comprising an aqueous solvent in a concentration comprised between 30 and 55% w/w with respect to the weight of the ink, more preferably comprised between 35 and 50% w/w. 
     
     
         12 . The ink according to  claim 9 , comprising at least one binding agent in a concentration comprised between 5 and 20% w/w with respect to the weight of the ink, preferably said at least one binding agent is at least one resin. 
     
     
         13 . A printing process for forming at least one image or writing on at least one substrate, comprising at least one step of using an ink according to  claim 9 . 
     
     
         14 . The process according to  claim 13 , wherein the printing is a piezoelectric ink-jet printing with drop-on-demand technology. 
     
     
         15 . The process according to  claim 13 , wherein the printing process has a printing speed comprised between 5 and 300 metres/minute, preferably comprised between 80 and 250 metres/minute.